officials say tammerlan and jahar tsarnaev planned to set off bombs in times square. this plot hatched spontaneous lay cording to the police commissioner while driving around in an suv hijacked thursday night. >> they realized the vehicle was low on gas and ordered the driver to stop in a gas station. the driver used this opportunity to escape and call the police. >> on capitol hill today republican senator lindsay gram blamed the obama administration because neither the fbi nor cia knew that tammerlan had been advocating jihad against the united states for months online. >> we were unable to connect the dots and pick that up. the rest is history. between benghazi and boston, our systems are failing and we're going backward. >> the fbi searched a landfill today looking for explosives the suspects might have used for practice. >> bart taking a look at emergency preparedness. the police chief briefed the board on steps taken after the bombings and what still needs to be done. >> this exercise was just a drill but highlights the very real threat to the transportation sys